Carleman Approximation for certain sets with an isolated singularity

In this paper, we prove that local polynomial convexity at the origin for
the union of finitely many transverse totally real subspaces of maximal dimension
is sufficient for Carleman approximation.
Some new conditions are given for the polynomial convexity of the union of three transverse totally real planes in $\mathbb{C}^2$.
We also provide a sufficient condition on the union of two Lipschitz graphs for Carleman approximation. Along the way, we provide sufficient conditions for union of two Lipschitz graphs to be polynomially convex.
Finally, we find a family of surfaces in $\mathbb{C}^2$ with a hyperbolic complex point that allows Carleman approximation.